IBM Support

Starting FLEXlm service results in "Server unable to setup IPC channel" error in log

Technote (troubleshooting)


Attempts to start the FLEXlm service result in the error "Server unable to setup IPC channel".


The following is an example of the license server log.

16:24:57 (lmgrd) FLEXnet Licensing (v11.8.0.0 build 81116 i86_lsb) started on <hostname> (linux) (1/21/2014)
16:24:57 (lmgrd) Copyright (c) 1988-2009 Flexera Software, Inc. All Rights Reserved.
16:24:57 (lmgrd) US Patents 5,390,297 and 5,671,412.
16:24:57 (lmgrd) World Wide Web:

16:24:57 (lmgrd) License file(s): /<path_to>/Rational/config/<hostname>.dat
16:24:57 (lmgrd) lmgrd tcp-port 27000
16:24:57 (lmgrd) Starting vendor daemons ...
16:24:57 (lmgrd) Started ibmratl (internet tcp_port 42023 pid 15989)
16:24:57 (ibmratl) FLEXnet Licensing version v11.8.0.0 build 81116 i86_lsb
16:24:57 (ibmratl) Server started on <hostname> for: PurifyPlusUNIX
16:24:57 (ibmratl) EXTERNAL FILTERS are OFF
16:24:57 (lmgrd) ibmratl using TCP-port 42023
16:24:57 (ibmratl) Serving features for the following vendor names: ibmratl rational telelogic tlog_rhaps tlog_state
16:24:57 (ibmratl) Server unable to setup IPC channel
16:24:57 (ibmratl) EXITING DUE TO SIGNAL 39 Exit reason 7
16:24:57 (lmgrd) ibmratl exited with status 39 (Couldn't find a master)


This is due to being enabled for Dual Stack Communication for IPv4 and IPv6 on the machine that has IPv6 capability.

This issue can also occur when there are incorrect entries in the hosts file.

Resolving the problem


  1. Edit the hosts file (/etc/hosts)

  2. Comment out the ::1 entry which pertains to the IPv6 localhost definition

  3. Save and close the hosts file

  4. Start FLEXlm service

Document information

More support for: Rational License Key Server

Software version: Version Independent

Operating system(s): Linux, Solaris

Reference #: 1584722

Modified date: 27 January 2014